Schweitzer Engineering SEL-351P - Additional Local Control Switch Application Ideas; Local Control Switch States Retained; Power Loss

Date Code 990215 Inputs, Outputs, Timers, and Other Control Logic 7-9
SEL-351P Manual Técnico
To keep reclosing from being initiated for this trip example, set local bit LB3 to drive the
reclosing relay to lockout for a manual trip example (see Section 6: Close and Reclose Logic):
79DTL = ... + LB3
Figure SECTION 7: .8: Configured Manual Close Switch Drives Local Bit LB4
Local bit LB4 is set to close the circuit breaker in the following SEL
OGIC Control Equation
setting example:
CL = LB4
SEL
OGIC Control Equation setting CL is for close conditions, other than automatic reclosing or
serial port CLOSE command (see Figure 6.1 in Section 6: Close and Reclose Logic).
Additional Local Control Switch Application Ideas
The preceding factory settings examples are OFF/MOMENTARY switches. Local control
switches configured as ON/OFF switches can be used for such applications as:
• Reclosing relay enable/disable
• Ground relay enable/disable
• Remote control supervision
• Sequence coordination enable/disable
Local control switches can also be configured as ON/OFF/MOMENTARY switches for
applications that require such. Local control switches can be applied to almost any control
scheme that traditionally requires front-panel switches.
Local Control Switch States Retained
Power Loss
The states of the local bits (Relay Word bits LB1 through LB8) are retained if power to the relay
is lost and then restored. If a local control switch is in the ON position (corresponding local bit
is asserted to logical 1) when power is lost, it comes back in the ON position (corresponding
local bit is still asserted to logical 1) when power is restored. If a local control switch is in the
OFF position (corresponding local bit is deasserted to logical 0) when power is lost, it comes
back in the OFF position (corresponding local bit is still deasserted to logical 0) when power is